Motorcycle taillights (brake lights and running lights) and turn lights are typically external components mounted to frames or fenders. Taillights are provided as a reminder to following and nearby motorists of a motorcyclist's presence, and turn signals are provided to alert following motorists of a motorcyclist's upcoming movements. Traditionally, motorcycle taillights are mounted below the seat of the motorcycle. This placement results in an illumination that is close to the ground and often difficult to see by following motorists. Motorcycle back rests with illumination assemblies extending above the motorcycle seat have been developed. However, such assemblies provide only rearward illumination and are therefore less likely to be noticed by motorists driving alongside a motorcyclist. To this end, a need exists for a taillight assembly extending above a motorcycle seat and providing increased horizontal illumination. It is to such a taillight assembly that the inventive concepts disclosed herein are directed.